sys/shell: reduce overhead of XFA shell commands

We do not need to add an array of pointers to the shell commands, just
an array of shell commands is sufficient. This reduced the overhead of
XFA by `sizeof(void *)` per command.

sys/include/shell.h

@@ -283,15 +283,14 @@ int shell_parse_file(const shell_command_t *commands,
  * ```
  */
 #define SHELL_COMMAND(cmd, help, func) \
-    XFA_USE_CONST(shell_command_xfa_t*, shell_commands_xfa); \
+    XFA_USE_CONST(shell_command_xfa_t, shell_commands_xfa); \
     static FLASH_ATTR const char _xfa_ ## cmd ## _cmd_name[] = #cmd; \
     static FLASH_ATTR const char _xfa_ ## cmd ## _cmd_desc[] = help; \
-    static const shell_command_xfa_t _xfa_ ## cmd ## _cmd = { \
+    XFA_CONST(shell_commands_xfa, 0) shell_command_xfa_t _xfa_ ## cmd ## _cmd = { \
         .name = _xfa_ ## cmd ## _cmd_name, \
         .desc = _xfa_ ## cmd ## _cmd_desc, \
         .handler = &func \
-    }; \
-    XFA_ADD_PTR(shell_commands_xfa, cmd, cmd, &_xfa_ ## cmd ## _cmd)
+    };
 #endif /* __cplusplus */
 
 #ifdef __cplusplus

sys/shell/shell.c

@@ -47,7 +47,7 @@
 #endif
 
 /* define shell command cross file array */
-XFA_INIT_CONST(shell_command_xfa_t*, shell_commands_xfa);
+XFA_INIT_CONST(shell_command_xfa_t, shell_commands_xfa);
 
 #define ETX '\x03'  /** ASCII "End-of-Text", or Ctrl-C */
 #define EOT '\x04'  /** ASCII "End-of-Transmission", or Ctrl-D */
@@ -102,10 +102,10 @@ static shell_command_handler_t search_commands(const shell_command_t *entry,
 
 static shell_command_handler_t search_commands_xfa(char *command)
 {
-    unsigned n = XFA_LEN(shell_command_t*, shell_commands_xfa);
+    unsigned n = XFA_LEN(shell_command_t, shell_commands_xfa);
 
     for (unsigned i = 0; i < n; i++) {
-        const volatile shell_command_xfa_t *entry = shell_commands_xfa[i];
+        const volatile shell_command_xfa_t *entry = &shell_commands_xfa[i];
         if (flash_strcmp(command, entry->name) == 0) {
             return entry->handler;
         }
@@ -138,9 +138,9 @@ static void print_commands(const shell_command_t *entry)
 
 static void print_commands_xfa(void)
 {
-    unsigned n = XFA_LEN(shell_command_xfa_t*, shell_commands_xfa);
+    unsigned n = XFA_LEN(shell_command_xfa_t, shell_commands_xfa);
     for (unsigned i = 0; i < n; i++) {
-        const volatile shell_command_xfa_t *entry = shell_commands_xfa[i];
+        const volatile shell_command_xfa_t *entry = &shell_commands_xfa[i];
         printf("%-20" PRIsflash " %" PRIsflash "\n",
                      entry->name, entry->desc);
     }